C#EF6索引属性不起作用

Question

我正在尝试将两个字段组合成一个带有EF6的唯一索引.但update-database命令不会将"Owner"字段添加到索引中.我在想它是因为它不是原始类型而是FK,但我不确定如何解决它.

public class Fund
{
    [Key]
    public int FundId { get; set; }

    [Required]
    [Index("IX_FundNameAndOwner", IsUnique = true, Order = 1)]
    [Index("IX_FundIdentifierAndOwner", IsUnique = true, Order=1)]
    public ApplicationUser Owner { get; set; }


    [Required]
    [Index("IX_FundNameAndOwner", IsUnique = true, Order=2)]
    [MaxLength(25)]
    public string Name { get; set; }

    [Required]
    [Index("IX_FundIdentifierAndOwner", IsUnique = true, Order=2)]
    [MaxLength(25)]
    public string Identifier { get; set; }

    public double Balance { get; set; }
}

生成的索引:

创建独特的非集群索引[IX_FundIdentifierAndOwner] ON [dbo].[Funds]([Identifier] ASC);

创建独特的非集群索引[IX_FundNameAndOwner] ON [dbo].[Funds]([Name] ASC);

创建非集群索引[IX_Owner_Id] ON [dbo].[Funds]([Owner_Id] ASC);

任何帮助是极大的赞赏!

Answer 1

当您创建导航属性（引用另一个表）时，您应该指定用作外键的列名。如果您不这样做，EF 会假定它是一个名为 Objectname_Id 的列。

您可以在 sql 代码中看到它调用您的列 [Owner_Id]。问题是，当您这样做时，您无法控制该列的数据注释。

尝试这个

public class Fund
{
    [Key]
    public int FundId { get; set; }

    [Required]
    [Index("IX_FundNameAndOwner", IsUnique = true, Order = 1)]
    [Index("IX_FundIdentifierAndOwner", IsUnique = true, Order = 1)]
    public int OwnerId { get; set; } // <---- ADD THIS!

    public virtual ApplicationUser Owner { get; set; }


    [Required]
    [Index("IX_FundNameAndOwner", IsUnique = true, Order = 2)]
    [MaxLength(25)]
    public string Name { get; set; }

    [Required]
    [Index("IX_FundIdentifierAndOwner", IsUnique = true, Order = 2)]
    [MaxLength(25)]
    public string Identifier { get; set; }

    public double Balance { get; set; }
}

添加名为 ObjectId（或 Objec_Id）的列 EF 按照约定理解该列是针对属性 Owner 的。

这是迁移生成的脚本：

CREATE TABLE [dbo].[Funds] (
    [FundId] [int] NOT NULL IDENTITY,
    [OwnerId] [int] NOT NULL,
    [Name] [nvarchar](25) NOT NULL,
    [Identifier] [nvarchar](25) NOT NULL,
    [Balance] [float] NOT NULL,
    CONSTRAINT [PK_dbo.Funds] PRIMARY KEY ([FundId])
)
CREATE UNIQUE INDEX [IX_FundIdentifierAndOwner] ON [dbo].[Funds]([OwnerId], [Identifier])
CREATE UNIQUE INDEX [IX_FundNameAndOwner] ON [dbo].[Funds]([OwnerId], [Name])

以下是默认的Code First Conventions的解释。